This activity is about planetary climate. Once familiar with the factors that determine a planet's surface temperature, learners will use an interactive spreadsheet model of a planet's atmosphere to determine if greenhouse gases, luminosity of the...(View More) source, the distance of the planet from the source and the albedo of the planet can be manipulated so that the average surface temperature on Mars or Venus could support human life. Learners will then be asked to make some conclusions about these methods and suggest improvements for the spreadsheet model (see related resources for link to this model). The activity requires use of Microsoft Excel software. This is Activity D in the fourth module, titled "How do Atmospheres Affect Planetary Temperatures?," of "Earth Climate Course: What Determines a Planet's Climate?."(View Less)